Because otherwise plastic is miracle material. Alternatives are lot less practical or do not offer same advantages. Glass is heavier, less sturdy, possible pro

Because otherwise plastic is miracle material. Alternatives are lot less practical or do not offer same advantages. Glass is heavier, less sturdy, possible produces shards that cause immediate damage such as cuts. Most metals need the plastic coating to be non-reactive. And then products packed in plastic stored in inert gas last amazingly long time. Which is very big selling point for many customers.